Ink Set Pigment Resin Compatibility High-Speed Printing

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Solution Overview

Problem

Conventional inkjet inks struggle with achieving sharp image quality and minimizing mixed color bleeding when printing on low-absorption substrates like PET films, especially during high-speed printing.

Innovation Solution

The use of an ink set comprising white and color inks, where each ink includes a pigment, a pigment dispersing resin with either an alkyl chain of 10 or greater or a polyoxyalkylene chain, and an organic solvent with specific properties, such as a boiling point between 180°C and 280°C and surface tension between 20 mN/m and 30 mN/m, to enhance printability and reduce compatibility between the inks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional aqueous inks are used for printing on low-absorption substrates, then the ink can be applied to the substrate, but the image blurs due to excessive absorption and mixed color bleeding occurs

Engineering Contradiction:
Improveimage sharpnessVSAvoidmixed color bleeding
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the ink composition by specifying precise ranges for surfactant concentration (0.01-5% by weight), organic solvent content (5-40% by weight), and pH (5.0-9.0). These parameter adjustments optimize the ink's interaction with low-absorption substrates to prevent both excessive absorption and mixed color bleeding, thereby improving image sharpness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink formulation combining multiple components: water-soluble polymers (0.1-20% by weight), surfactants, organic solvents, and pigments. This composite material approach allows the ink to achieve balanced properties for printing on low-absorption substrates without causing image blur or color mixing issues.

Inventive Principle:
Principle #40Composite materials

2Productivity

If high-speed printing is performed on less permeable substrates, then productivity increases, but image quality deteriorates due to mixed color bleeding

Engineering Contradiction:
Improveprinting speedVSAvoidimage sharpness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent optimizes volatile content (5-40% by weight) and surfactant concentration to control drying kinetics. These parameter changes enable the ink to dry at appropriate rates during high-speed printing, preventing mixed color bleeding while maintaining image sharpness and allowing increased productivity.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the ink composition is optimized for sharp images, then manufacturing precision improves, but the complexity of ink formulation increases

Engineering Contradiction:
Improveimage sharpnessVSAvoidink formulation complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent establishes specific parameter ranges (surfactant: 0.01-5%, organic solvent: 5-40%, pH: 5.0-9.0) that balance image sharpness with formulation simplicity. By defining these concrete parameters, the patent achieves manufacturing precision without excessive formulation complexity, making the ink practical for industrial application.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach results in excellent printability and sharp image quality with minimal mixed color bleeding on less permeable substrates, even at high printing speeds, by reducing the compatibility between the inks and improving drying properties.

Implementation Method 1

an organic solvent having a boiling point of at least 180°C but not more than 280°C and a surface tension of at least 20 mN/m but not more than 30 mN/m

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

a surface tension of at least 20 mN/m but not more than 30 mN/m

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP3260507B1Ink set for ink-jet recording
Publication Date: 2020.05.20 TOYO INK MFG CO LTD

AI summary

The present invention relates to an ink set for inkjet recording containing a white ink and color inks including a cyan ink, a magenta ink and a yellow ink, wherein each ink independently contains a pigment, a pigment dispersing resin, an organic solvent and water, the pigment dispersing resin A of either the white ink or the color inks has an alkyl chain with a carbon number of 10 or greater, the pigment dispersing resin B of the other of the white ink or the color inks has a polyoxyalkylene chain, and the pigment dispersing resin A and the pigment dispersing resin B are different resins. According to the present invention, an ink set for inkjet recording can be provided that exhibits excellent printability during high-speed printing, even when printing onto less permeable substrates, and is capable of producing sharp image quality with little mixed color bleeding.